We have developed a system to condition culture media with the cochlear sensory epithelium of the chick. Experiments using this media to culture dissociated chick auditory ganglion cells demonstrate an increase in neuronal survival when compared to controls. Our preliminary data indicates that one or more neurotrophic factors are released from the chick cochlear sensory epithelium. We are planning studies to identify these factors and to conduct additional experiments in rats to determine if the same or similar factors are released by the mammalian organ of Corti.